The prior request was withdrawn after the Swiss Federal Administrative Court rejected it. Per the article:
The court held that the request -- which didn't specifically identify the names of targeted bank clients but instead sought information on clients who had allegedly concealed U.S. income and assets with the assistance of bank employees -- was too vague, was based on search criteria indicating only tax evasion and not tax fraud, and was not sufficient to require cooperation by the Swiss tax authorities under the current Switzerland-U.S. tax treaty.The TNT article cites a Swiss newspaper as indicating that (i) the reformulated request provides "a more detailed description of the manner in which the bank and clients concealed U.S. income and assets"; (ii) the "FTA directed Credit Suisse to inform affected clients by July 31 that their information is subject to disclosure under a treaty request made by U.S. authorities;" and (iii) "The new request affects fewer than 100 U.S. clients."
U.S. Makes New Request to Swiss for Information on Alleged Tax Cheats (adr.com 8/30/12), here.